The San Diego North Chamber of Commerce, with the support of politicians and business officials, rolled out a sweeping regional Think Local First campaign to encourage San Diego County residents, businesses and government agencies to buy their goods and services locally.

Keeping dollars in the county has a host of social, economic and even environmental benefits, said Chamber CEO Debra Rosen last week at a news conference announcing the initiative, modeled after a statewide campaign of the same name in New Mexico.

It has already gained the support of three other chambers of commerce and 18 elected officials, including Congressman Scott Peters and County Board of Supervisors Chairman Greg Cox.

"For every hundred dollars spent at a local business $43-$68 goes back into the community and our tax base," Rosen said during the conference held at the Courtyard by Marriott in Rancho Bernardo.

Those tax dollars are then spent on roads, sidewalks, streetlights and other public amenities, she said.

Sales and use tax dollars in San Diego, Chula Vista and Poway in fiscal year 2011 totaled $174.4 million, $20 million and $7.8 million, respectively, according to a draft economic impact report commissioned by the chamber. A full 36 percent of Escondido's $72 million general fund is generated by sales tax.

If every resident of Poway spent an additional $2,000 per year inside the city, Rosen said, Poway would realize more than $900,000 in additional sales tax revenue to help pay for police, fire, and other infrastructure upgrades.

Critics of the buy-local movement say it can mean limited product selection and higher prices for consumers, and less efficient manufacturing and transportation for suppliers.

But making purchases close to home supports businesses that have made a capital investment commitment to the region by putting roots down in San Diego County, said Assemblyman Brian Maienschein.

"These types of businesses help to stabilize our economy with direct injections of money that benefit our residents," he said. "These benefits include infrastructure for existing and new projects, as well as public safety."

Derrick Breaux, publisher of ZCode Magazines, a group of nine community-based magazines in San Diego County, said his 250 or so local advertisers are primarily brick-and-mortar firms who rely heavily on a purchasing radius of 5 to 7 miles for their consumers.

"They depend so much on their local community to welcome them," Breaux said.

Urge American Gastropub cofounder Zak Higson said that despite some of the challenges of purchasing locally, he hopes the campaign resets people's focus onto the public benefits of doing so.

District 3 Supervisor Dave Roberts said he is working with his staff to include a clause in all grant contracts he issues, requiring the money to be spent inside the county.